The construction depends on three parameters: an integer aspect ratio \(A>1\) , an integer scale factor \(\rho >1\) , and a number of steps \(i\) . In [1]}, one starts with a function \(\psi _0=0\)  and constructs \(\psi _{i+1}\)  by perturbing \(\psi _i\) . The difference \(\psi _{i+1}-\psi _i\)  is a sum of bump functions supported on regions in \(V_0\)  with aspect ratio \(A\) , and the scale of the perturbations decreases by a factor of \(\rho \)  at each step.
